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        검색결과 127

        122.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        The materials flow of nickel was analyzed into up-stream and down-stream based on the literature survey. Dischargeand recycling stages in the down-stream were analyzed through the field survey. The waste nickel resources circulationflow were analyzed into 4 stages such as discharge·import, collection·disuse, resource recovery and product production·export, which are divided into nickel scrap and stainless steel scrap. The nickel scrap of 1,500ton was collected andrecycled and exported, which are from battery, catalyst and etc. The stainless steel scrap of 55,200ton are recycled fromdomestic and imported sources, which are 28,800ton and 26,400ton, respectively. The resource circulation rate of 45.3%is obtained from the above flow and the various plans are suggested each stage to increase resource circulation rate. Atdischarge·import stage, it is suggested this kind of waste may be classified as resources if the classification of waste isdone in detail and suitably. Also, it is suggested to apply quota tariff to this kind of waste. At collection·disuse stage, theplan of stabilizing supply and demand is suggested through the improvement of bidding system. At resource recovery stage,the fostering plan for specialized crushing companies and the win-win plan between conglomerate and medium-smallcompanies are suggested. At product production·export stage, it is suggested the integrated approval for licensing to registeras waste-treating facilities instead of exempting registration under the present condition to activate recycling industries.
        124.
        2010.09 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 라테라이트광의 건식 분쇄가 니켈 및 코발트의 침출에 미치는 영향을 조사하였다. 시료로 사용한 라테라이트광은 주로 SiO2, Fe2O3, MgO로 이루어져 있으며, 니켈과 코발트의 함량은 0.81% Ni, 0.02% Co이었다. 주 구성 광물은 리자다이트와 석영이며, 미량의 포스터라이트와 엔스터타이트를 함유하고 있었다. 분쇄가 진행됨에 따라 시료의 평균입도, 비표면적, 밀도는 감소하는 경향을 보였으며, X-선 회절분석을 통해 리자다이트의 비정질화가 진행됨을 확인하였다. 분쇄에 의한 석영의 물성변화는 나타나지 않았으나, 리자다이트의 Mg-OH 결합이 파괴됨으로써 니켈 및 코발트의 침출율이 향상됨을 알 수 있었다. 분쇄가 진행됨에 따라 니켈과 코발트의 침출율은 증가하였으며, 60분 분쇄한 시료의 경우, 사용한 무기산의 종류에 관계없이 니켈과 코발트의 침출율은 약 80%로 나타났다.
        125.
        2010.09 KCI 등재 서비스 종료(열람 제한)
        고순도 니켈 금속염으로부터 미세하고 입도가 균일한 니켈 분말 직접 제조 연구를 수행하였다. 구형의 형상을 갖는 미세한 니켈 분말을 제조하기 위하여 입도제어가 가능한 슬러리환원법을 사용하였다. 제조된 니켈 분말에 화학성분, 입도, X선회절, 주사전자현미경 분석을 실시하여 니켈 분말의 특성을 조사하였다. 환원제로 하이드라진(hydrazine)을 사용하고, 4.5 M NaOH에서 90분 반응시켜 약 100~200 nm의 입도를 가진 분산도가 양호한 구형의 니켈 분말을 제조할 수 있었다.
        127.
        2004.08 KCI 등재 서비스 종료(열람 제한)
        The effect of nickel (Ni) on growth and some tolerance strategies with regard to heavy metal tolerance mechanism was investigated in radish (Raphanus sativus) seedlings. The protective effect of histidine on nickel stress conditions was also monitored. The seedling growth decreased with an increase in metal concentrations. The inhibitory effect was more pronounced in the root elongation than in the shoot elongation. Increasing Ni supply showed a progressive increase of Ni concentrations in the roots and shoots. Ni content was higher in the shoots than in the roots. In the presence of nickel, radish exhibited an antioxidative defense mechanism, as evidenced by the elevated malondialdehyde(MDA), showing that nickel is an efficient inducer of lipid peroxidation. Exposure of radish to elevated concentrations of nickel was accompanied by an increase in the proline content. Supplemental histidine in the presence of Ni ameliorated metal-induced growth inhibition and lipid peroxidation. Combinations of Ni and histidine resulted in a significant decline in proline content compared with Ni stress alone, indicating that histidine may provide protection against the adverse effect of Ni stress. From the results it is suggested that histidine is an efficient chelator by complexing metal ion within the plant and may play a role in nickel tolerance implicated in metal detoxification.
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